Subsurface pavement imaging and mapping using IRIS-4 Vehicle (1ns/1GHz antenna array

Applications
 
Pavement Structure
  Pavement Layer Thickness
  Voids Beneath Pavements
  Detection of Subsurface Moisture
  Concrete Deterioration

GPR Data Collection
GPR Data Analysis & Results
 
Our GPR highway inspection provides information on pavement structure and layer thickness, and our surveys can detect various forms of pavement deterioration, voids and regions of excessive subsurface moisture. We utilize state-or-the-art IRIS non-contacting GPR equipment operating at highway speed and requiring no traffic control. GPR can cover several hundred lane miles per day, making this technology ideal for network level and project level inspection of highway pavement. Penetradar’s pavement surveys produce graphical and numerical results that are easily understood and readily usable by pavement and maintenance engineers.



Subsurface pavement profiling using 1ns/1GHz and 2ns/500MHz non-contacting, horn antennas.

Analysis is performed on the data from each radar to determine total thickness of asphalt layer and base layer (where possible), on a continuous basis and reported at 1 foot intervals. Alternate thickness reporting intervals can also be provided. The output is presented in an ASCII file format (that can be exported to a Pavement Management Database - PMS) and/or plan view color topographical format.  

Analysis of GPR data is performed to determine areas of high moisture accumulation in the pavement subbase region. Relative moisture measurements are typically reported on at 1 foot intervals in an ASCII file format which can then be imported to a PMS Database.  Relative moisture measurements can also be depicted in a plan-view moisture map of the pavement surface.

GPR can indicate locations of subsurface air-filled and water-filled voids. Voids as small as 1/8 inch under rigid pavements are typically detected and reported. The survey is typically conducted using the two or more GPR units inspecting the wheel tracks as a minimum. Void locations are reported in an ASCII file, listing location, or with multiple GPR scans, a plan view mapping of void locations can also be produced which provides spatial locations of voids, as well as individual and total void area.

GPR can detect concrete pavement deterioration on exposed concrete pavements or those with an asphalt riding surface. Although, this technique is typically utilized for asphalt overlaid concrete pavements where visual examination is not possible.  The survey is typically conducted using three or more non-contacting GPR antennas inspecting the wheel tracks and center lane. Deteriorated regions are reported in an ASCII file listing distance and location. With multiple GPR antenna scans, plan-view mappings of deterioration locations can also be provided showing spatial locations and the total area of deteriorated concrete.  

GPR is an effective means of detecting and identifying subsurface anomalies such as full depth pavement patches, man-hole covers overlaid with asphalt, buried utilities and utility cuts, and abandoned rail and trolley tracks. The survey is typically conducted with an array of antennas of varying frequency and depth range. Anomalies are reported in an ASCII file listing distance, location, depth and description of the anomaly.  

FIELD TEST:

Data acquisition rate of up to 300 lane-miles per day can be achieved depending upon the type of survey and site conditions. The GPR survey can be conducted during the day or evening, and Traffic Control is not required.